They have a characteristic U shape in cross-section, with steep, straight sides and a flat or rounded bottom (by contrast, valleys carved by rivers tend to be V-shaped in cross-section). Glaciated valleys are formed when a glacier travels across and down a slope, carving the valley by the action of scouring .
How are valleys formed by rivers different from valleys formed by glaciers?
Valley glaciers carve U-shaped valleys , as opposed to the V-shaped valleys carved by rivers. During periods when Earth’s climate cools, glaciers form and begin to flow downslope. Often, they take the easiest path, occupying the low V-shaped valleys once carved by rivers.
What is the difference between glacial valley and river valley?
The formation of glacial valleys does not depend on the gradient but only the volume of the glacier . Larger glaciers carve larger, wider valleysRiver valleys are formed due to the kinetic energy of rivers falling from a steep height.
How are valleys created?
These geological formations are created by running rivers and shifting glaciers . Valleys are depressed areas of land–scoured and washed out by the conspiring forces of gravity, water, and ice.
Are glacial valleys deeper than river valleys?
These glacial troughs may be several thousand feet deep and tens of miles long. ... Because a glacier has a much greater viscosity and cross section than a river, its course has fewer and broader bends, and thus, the valley becomes straighter and smoother.
How can you tell from your profile that the valley was formed by a glacier?
They have a characteristic U shape in cross-section, with steep, straight sides and a flat or rounded bottom (by contrast, valleys carved by rivers tend to be V-shaped in cross-section). Glaciated valleys are formed when a glacier travels across and down a slope, carving the valley by the action of scouring .
Is a hanging valley erosion or deposition?
U-shaped valleys, hanging valleys, cirques, horns, and aretes are features sculpted by ice. The eroded material is later deposited as large glacial erratics, in moraines, stratified drift, outwash plains, and drumlins. Varves are a very useful yearly deposit that forms in glacial lakes.
How do valleys affect humans?
Since the beginning of human development, valleys have been an important place for people because of their presence close to rivers . Rivers enabled easier movement and also provided resources like water, good soils, and food such as fish.
What animals live in valleys?
Native grasslands supported several herbivores including pronghorn antelope (Antilocarpa americana), elk (including a valley subspecies, the Tule Elk, (Cervus elaphus nannodes), mule deer (Odocoileus hemionus), California ground squirrels, gophers, mice, hare, rabbits, and kangaroo rats.
How do valleys affect climate?
Since a river or stream often flows through a valley, this increases the moisture . This combined with cooler temperatures at night can result in valley fog and clouds. If an inversion is in place, the fog, clouds and/or smog can persist in the valley during the day. Strong wind events can occur in a valley.
Which is the best description of glacial till?
Glacial till is the sediment deposited by a glacier . It blankets glacier forefields, can be mounded to form moraines and other glacier landforms, and is ubiquitous in glacial environments.
What is the end of a valley called?
The head of the valley or, less commonly, the valley head , refers to the uppermost part of a valley.
Why waterfalls are formed in hanging valley?
When the glaciers retreat from the area where they formerly met, the floor of the u-shaped valley formed by the smaller glacier may be many feet above the main valley. ... Waterfalls often form at this point when rivers begin flow through the glacier valleys .
Where is a famous U shaped valley?
Yosemite Valley, California is an example of a U shaped glacial valley.
What are the sides of a valley called?
A valley has a “head” where it begins in the mountains or hills, “sides” where it rises up on either side, a “ floor ” which is where the valley is most flat. Some valleys have an “entrance” where the valley opening can be seen between two hills or mountains or cliffs.
What are the main features of glacial erosion?
As the glaciers expand, due to their accumulating weight of snow and ice they crush and abrade and scour surfaces such as rocks and bedrock. The resulting erosional landforms include striations, cirques, glacial horns, arêtes, trim lines, U-shaped valleys, roches moutonnées, overdeepenings and hanging valleys
